1. Field of the Invention
The present invention relates to the alkylation of paraffinic hydrocarbon feed stocks wherein an olefin is reacted with isobutane to produce an alkylate product. More particularly the invention relates to a process wherein an intermediate debutanizer is utilized between two alkylation systems to provide a first alkylate product and a concentrated isobutane stream for use in a the second alkylation system. The process eliminates the need for a second deisobutanizer.
2. Related Information
Alkylation is the reaction of a paraffin, usually isoparaffins, with an olefin in the presence of a strong acid which produces paraffins, e.g., of higher octane number than the starting materials and which boil in range of gasolines. In petroleum refining the reaction is generally the reaction of a C3 to C5 olefin with isobutane.
In refining alkylations, hydrofluoric or sulfuric acid catalysts are most widely used. For sulfuric acid catalyzed alkylation low temperature or cold acid processes are favored because side reactions are minimized. In the traditional process the reaction is carried out in a reactor where the hydrocarbon reactants are dispersed into a continuous acid phase. In view of the fact that the cold acid process will continue to be the process of choice, various proposals have been made to improve and enhance the reaction and, to some extent, moderate the undesirable effects.